CODEWITHSUNDEEP
javaandroid
vicolored
vicolored

Reputation: 835

Cannot append text to File

My code is :

if(myfile.exists()) {
    try {
        FileOutputStream fOut = new FileOutputStream(myfile);
        OutputStreamWriter myOutWriter =  new OutputStreamWriter(fOut);
        for (LatLng item : markerArrayList) {
            myOutWriter.append(item.toString());
        }
        myOutWriter.append("\n\n");
        myOutWriter.close();
        fOut.close();
        Toast.makeText(getBaseContext(), "Done writing ", Toast.LENGTH_SHORT).show();
    } catch (Exception e) {
        Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
    }        
}

When I use myOutWriter.append, what really happens is that every time I'm writing to the file, it overwrites previous content.

Upvotes: 5

Views: 689

Answers (3)

Nitram
Nitram

Reputation: 6716

The problem is that the cursor that is marking the place where the OutputStreamWriter is starting to write into the file is at the very beginning of the file.

What you want to do is to set it to the end of the file using the alternative constructor of FileOutputStream that has a boolean attribute. The fixed code would be:

if(myfile.exists()) {
    try {
        FileOutputStream fOut = new FileOutputStream(myfile, true);
        OutputStreamWriter myOutWriter =  new OutputStreamWriter(fOut);
        for (LatLng item : markerArrayList) {
            myOutWriter.append(item.toString());
        }
        myOutWriter.append("\n\n");
        myOutWriter.close();
        fOut.close();
        Toast.makeText(getBaseContext(), "Done writing ", Toast.LENGTH_SHORT).show();
    } catch (Exception e) {
        Toast.makeText(getBaseContext(), e.getMessage(),
                Toast.LENGTH_SHORT).show();
    }
}

Upvotes: 1

Sachin Gupta
Sachin Gupta

Reputation: 8358

use FileOutputStream's secondconstructor :

FileOutputStream(String name, boolean append)

with append value as true

Upvotes: 2

vefthym
vefthym

Reputation: 7462

That's because you do not use the append option of the FileOutputStream constructor.

You should use:

FileOutputStream fOut = new FileOutputStream(myfile, true);

instead, to open the file for appending.

Otherwise, it overwrites the contents of the previous file.

Upvotes: 7

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